GRAND RAIPDS, MI -- A Union High School student was reportedly found with a handgun this morning and police converged on the school, believing another student may also be armed, according to police dispatch traffic.

The school, 1800 Tremont Blvd. NW, was on lockdown for a period until police and school authorities determined the other student was not in class.

Police were called about 10:30 a.m. to Union and requested a dog to search the facility, according to dispatch traffic.

School authorities lifted the "code red" lockdown after about 15 minutes when it was determined the other student was not there.

The student found with the gun was being detained.

In a statement, Grand Rapids Schools spokesman John Helmholdt indicated the gun was found after school security approached a student "as part of an ongoing investigation."

The student was escorted to an office and searched. Security staff then found the gun.